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Rainy days The current La Niña weather pattern is likely to continue for at least another month according to the latest forecast from the Bureau of Meteorology.

The news means more wet weather for the already rain soaked eastern parts of Australia.

Manager of the Bureau's Climate Prediction Services, Dr Andrew Watkins says, "The current the La Niña is fairly steady".

La Niña happens when the tropical eastern Pacific Ocean starts to cool down meaning more warm water near Australia. This causes more cloud, and hence rainfall, over the country's east.

The opposite, El Niño appears when the tropical eastern Pacific starts to warm up, resulting in cooler oceans near Australia with less clouds and reduced rainfall.

According to Watkins La Niña's tend to start breaking down around January, ending in autumn.

"It started backing off during December and the first half of January," says Watkins. "But we've seen a few events in the last couple of weeks that have cooled things down in the eastern Pacific, so La Niña continues with really not a great deal of change."

"Most of our latest climate models indicate it should start backing off and having a bit of decline - meaning temperatures in the eastern Pacific will start warming up - and head back to neutral conditions around mid-autumn," says Watkins.

La Niña periods are usually, but not always, associated with above normal rainfall and below normal daytime temperatures from winter through summer across eastern and northern Australia.

Tropical cyclone risk is increased for northern Australia during the cyclone season from November to April, peaking in February and March.

Climate Change

According to Watkins, "The science is still out on how climate change impacts on El Niños and La Niñas".

"We know climate change has already resulted an about 0.5°C warming of the Pacific Ocean and that tends to favour the El Niño side of things," says Watkins.

"But it's also effected the Southern Oscillation Index in the atmosphere in the opposite way giving a bit more of a La Niña-type signal."

Watkins says having two La Niñas in a row isn't unusual.

"Back in the 1970's we had four La Niña events in a row," he says. "We've had an unusual set of years since the turn of the century with back-to-back El Niños and La Niñas."

"We've swung from one end of the cycle to the other, giving us wide swings in our weather from drought to flooding rains."

"We haven't had long periods in neutral conditions, lots of people have forgotten what the average weather is."